With the evolution of optoelectronics and semiconductor technology, it also brings the vigorous development of the flat panel display industry. In such many flat panel display, the liquid crystal display becomes the main product of the display market because it owns many superior characteristics of high space utilization efficiency, low power consumption, no radiation and low electromagnetic interference.
The liquid crystal display device usually comprises a liquid crystal panel and a backlight module. Because the liquid crystal display cannot illuminate by itself, the backlight module is assembled under the liquid crystal panel to provide the liquid crystal panel with the surface light source. Hence, the liquid crystal panel can display images via the surface light source from the backlight module.
In the prior art, the backlight module mainly comprises a plastic frame, optical films, light source, a light guide and a back plate. The light guide which one of its incident planes receives the light from the light source is installed on the back plate, and the light guide turns the light into the surface light source. The optical films installed on the light guide homogenize the surface light source and enhance the brightness of the surface light source. The plastic frame and the back plane are set together to fix the light guide, the light source and the optical films between the plastic frame and the back plate.
In recent years, the liquid crystal display device requires the more and more narrow frame, and the frame of the backlight module also meets the same requirement correspondingly. For the purpose of achieving the narrow boarder design of the backlight module, one mean is that the back plate is eliminated but it will greatly reduce the mechanical strength of the whole backlight module. Another mean is that the plastic frame is designed to be narrower but it only has the smaller degree of the narrow boarder design of the backlight module. Another mean is that the width of the sidewall of the back plate is reduced to achieve the narrow boarder design but it influences the cooling performance of the backlight module. The other mean is that the light source is designed on the sidewall of the back plate so as to achieve the narrow boarder design, and enhance the whole cooling performance of the backlight module; however, the plastic frame and the front frame (used for fixing the liquid crystal panel on the backlight module) cannot achieve the effective positioning.